For the lower hose, we used the F-body one again and cut about one inch off of it so it would fit. That smaller green hose is a "steam hose." The LT1 has a port on the back of each head that is designed to let air pockets (steam) out of the heads to prevent hot spots. The steam lines then travel to the throttle body to warm up the air/fuel mixture on cold days and then to the radiator. Some delete the steam lines through the throttle body, but since the lines weren't leaking and this Jeep will see snow and ice, we let them be and ran the steam line from the throttle body to the radiator. We cut about 5 1/2 inches off of the stock silicone Caprice line.